1. Field of the Invention
The present invention relates generally to carpentry tools and more particularly to an automatically retracting chalk line dispenser for conveniently dispensing and retracting a chalked string, such as those commonly used by carpenters to form straight lines.
2. Related Art
Chalk lines are used by carpenters and other building tradesmen to mark straight lines between two end points on a work surface. A line is “drawn” by stretching a chalk-covered string over the work surface between the two designated end points and snapping the string to release the chalk. The chalk line designates a straight line from one end point to the other, since the string that makes the line is stretched tightly between the two end points.
Contemporary chalk line dispensers typically comprise a housing in which a quantity of chalk dust may be disposed and inside of which a spool of string is pivotally mounted such that the string may be extended from the housing while carrying thereupon a small amount of chalk dust. The string is extended such that it coincides with a line for which marking is desired. The string is then held stationary at both ends and plucked near the middle such that chalk dust is shaken from the string when the string impacts the surface to be marked, thereby forming a straight line between the two ends of the string. A line catch or hook may be utilized to anchor the string at the distal terminus of the line to be formed while the chalk line device is held stationary at the lines proximal the terminus by the user. The string is typically manually retracted into the device via a rotatable handle and winding mechanism. The disadvantages with this type of device is the time, effort, and physical ability required to retract the string.
U.S. Pat. No. 4,197,656 to Lane et al. discloses an automatically retracting chalk line dispenser having a drive casing, a reel casing, and a thumb-operated lever for releasing a clutch to enable spring reeling of the line. Lane does not disclose a thumb-operated lever which acts as both a clutch and a brake, nor does Lane disclose an eyelet for securing the chalk line dispenser.
U.S. Pat. No. 5,509,616 to Millen, Jr. et al. discloses an automatically retracting chalk line dispenser including a casing forming a chalk reservoir, a spool assembly, and an automatic centrifugal speed regulator assembly. Millen discloses a complex and expensive device for regulating the speed of the chalk line rewinding. Millen does not disclose an inexpensive and reliable device for regulating chalk line rewind speed.
U.S. Pat. No. 5,727,324 to Moore discloses a manually retractable chalk line dispenser having a tearddrop-shaped main body. Moore does not disclose automatic retraction of the chalk line nor a simple device for locking extended chalk line. Also, Moore does not disclose an eyelet for securing the chalk line dispenser.
There remains a need in the art for an automatically retracting chalk line dispenser having structure to simplify its use and effective chalk line control mechanisms for increased functionality.